Background: Heart failure (HF) in children is a clinical and pathophysiological syndrome that results from ventricular dysfunction, volume or pressure overload, either alone or in combination. This study aimed to estimate serum level of H-FABP before and after treatment of congestive heart failure, and correlate its level with severity of the disease. Patients and methods: The study was cohort control study. It included 30 infants and children; their ages ranged from two months to four years with heart failure diagnosed clinically and were admitted to Cardiology Unit of Pediatric Department, at Zagazig University Hospitals during the period from November 2017 to April 2018. They were divided into four groups, first group aged (2-12 month), second group (13-24 m), third group (25-36 m) and fourth group (37-48 m). Echocardiographic assessment of the heart was done using conventional Doppler echocardiography. Serum heart type fatty acid binding protein (H-FABP) level (estimated on patient admission and 1 week after treatment) was determined by quantitative sandwich enzyme linked immunosorbent assay (ELISA) technique. Results: There was a significant difference in the serum level of H-FABP in our patients before treatment (2.156 ± 1.156 ng/ml) compared with after treatment (0.882 ± 0.716 ng/ml). There was a significant positive correlation between serum H-FABP level and Ross classification. Conclusion: H-FABP may be used as diagnostic and prognostic predictor of adverse outcome in children with heart failure.